A000853 Number of n-input 2-output switching networks under action of complementing group C(2,n) on inputs and S(2) and C(2,2) on outputs. (Formerly M3054 N1238)

3, 18, 1200, 33601536, 72057597192044544, 664613997892457950142846397346480128, 113078212145816597093331040047546785266841516594958545044409945396273479680

Offset

1,1

References

M. A. Harrison, On the number of classes of switching networks, J. Franklin Instit., 276 (1963), 313-327.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..10

Index entries for sequences related to switching networks

Formula

a(n) = (4^(2^n)+6*(2^n-1)*4^(2^(n-1))+2^(2^n+1))/2^(n+3). - Sean A. Irvine, Aug 11 2011

Maple

A000853:=n->(4^(2^n)+6*(2^n-1)*4^(2^(n-1))+2^(2^n+1))/2^(n+3): seq(A000853(n), n=1..8); # Wesley Ivan Hurt, May 03 2017

Prog

(Magma) [(4^(2^n)+6*(2^n-1)*4^(2^(n-1))+2^(2^n+1))/2^(n+3): n in [1..12]]; // Vincenzo Librandi, Aug 11 2011

Crossrefs

Sequence in context: A064846 A157544 A202946 * A065402 A131489 A069854

Adjacent sequences: A000850 A000851 A000852 * A000854 A000855 A000856

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

More terms from Sean A. Irvine, Aug 10 2011

Status

approved